| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.44 | 13 |
| 2015 | 6.895 | 20 |
| 2014 | 6.035 | 38 |
| 2013 | 6.988 | 33 |
| 2012 | 7.145 | 39 |
| 2011 | 4.94 | 76 |
| 2010 | 7.161 | 46 |
| 2009 | 3.398 | 60 |
| 2008 | 3.987 | 98 |
| 2007 | 7.58 | 70 |
| 2006 | 6.022 | 83 |
| 2005 | 5.785 | 76 |
| 2004 | 8.256 | 41 |
| 2003 | 5.495 | 55 |
| 2002 | 4.224 | 75 |
| 2001 | 4.036 | 78 |
| 2000 | 3.306 | 111 |
| 1999 | 4.524 | 60 |
| 1998 | 2.166 | 114 |
| 1997 | 5.104 | 64 |
| 1996 | 6.022 | 41 |
| 1995 | 4.424 | 56 |
| 1994 | 3.997 | 58 |
| 1993 | 2.434 | 72 |
| 1992 | 0.93 | 94 |
| 1991 | 0.326 | 88 |
| 1990 | 4.2 | 53 |
| 1989 | 6.409 | 28 |
| 1988 | 6.533 | 29 |
| 1987 | 4.905 | 42 |
| 1986 | 4.136 | 45 |